fix: improve file list management by limiting to max files and filtering oversized files

--bug=1059967 --user=刘瑞斌 【应用】高级编排上传文件最大数量设置为100，上传101个文件，不显示上传的文件，对话时上传文件为空 https://www.tapd.cn/62980211/s/1748567

ui/src/components/ai-chat/component/chat-input-operate/index.vue

@@ -423,13 +423,14 @@ const uploadFile = async (file: any, fileList: any) => {
     uploadOtherList.value.length
   if (file_limit_once >= maxFiles) {
     MsgWarning(t('chat.uploadFile.limitMessage1') + maxFiles + t('chat.uploadFile.limitMessage2'))
-    fileList.splice(0, fileList.length)
+    fileList.splice(0, fileList.length, ...fileList.slice(0, maxFiles))
     return
   }
   if (fileList.filter((f: any) => f.size > fileLimit * 1024 * 1024).length > 0) {
     // MB
     MsgWarning(t('chat.uploadFile.sizeLimit') + fileLimit + 'MB')
-    fileList.splice(0, fileList.length)
+    // 只保留未超出大小限制的文件
+    fileList.splice(0, fileList.length, ...fileList.filter((f: any) => f.size <= fileLimit * 1024 * 1024))
     return
   }
   const inner = reactive(file)